Sealed compressor and refrigeration device

ABSTRACT

In a sealed compressor ( 100 ) of the present invention, a suction muffler ( 160 ) includes a communication pipe ( 162 ) coupled to a suction hole ( 151   a ) of a valve plate ( 151 ). The communication pipe ( 162 ) extends upward from the suction muffler ( 160 ) toward the other end of a cylinder ( 133 ), and is provided at an upper end thereof with a communication pipe exit section ( 162   a ) which is in communication with the suction hole ( 151   a ). The cylinder head ( 152 ) is formed on a lower portion with a recess ( 152   d ) accommodating the communication pipe exit section ( 162   a ) therein. A gas inflow space ( 152   b ) in the interior of the sealed container is formed between the communication pipe exit section ( 162 ) and a recess ( 152   d ). The gas inflow space ( 152   b ) in the interior of the sealed container is a space which is in communication with a sealed space inside of the sealed container ( 101 ).

TECHNICAL FIELD

The present invention relates to a sealed compressor for use in a refrigeration cycle of refrigeration devices or the like, and a refrigeration device using the sealed compressor.

BACKGROUND ART

Refrigeration devices including refrigeration cycles are widely used for household purposes or business purposes, as home electric freezers/refrigerators, or show cases. In recent years, there has been an increasing demand for global environment conservation. Under the circumstances, there has been a strong demand for the high efficiency of a sealed compressor used in the refrigeration cycle.

Conventionally, as an example of a technique for preventing a decrease in the compression efficiency of the sealed compressor, an air compressor disclosed in Patent Literature 1 is known. This air compressor is configured such that a cylinder head is provided with a discharge chamber and a suction chamber, and a peripheral wall defining the discharge chamber and a peripheral wall defining the suction chamber are separated from each other by a cooling groove.

Specifically, as shown in FIG. 7, the air compressor disclosed in Patent Literature 1 includes a piston 512, a cylinder 513, a valve seat plate 514, a cylinder head 518, a suction valve 529, a discharge valve 531, etc.

The piston 512 reciprocates inside of the cylinder 513. The end surface of the cylinder 513 is provided with the valve seat plate 514. The valve seat plate 514 includes a suction port 528 and a discharge port (not shown) and is provided with a suction valve 529 and a discharge valve 531. The suction port 528 is opened and closed by the suction valve 529, while the discharge port is opened and closed by the discharge valve 531. A cylinder head 518 is provided above the valve seat plate 514. The cylinder head 518 includes a suction chamber 515 which is in communication with the suction port 528 and a discharge chamber 516 which is in communication with the discharge port.

The cylinder head 518 is formed by a single member and fastened to the cylinder 513 together with the valve seat plate 514. The suction chamber 515 defined by a peripheral wall 525 is provided at one side of the cylinder head 518. The discharge chamber 516 surrounds the peripheral wall 525 defining the suction chamber 515, and is defined by a peripheral wall 517 extending over the entire upper surface of the cylinder head 518. Between the peripheral wall 525 and the peripheral wall 517, a cooling groove 526 with a large depth is formed.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent No. 2688809

SUMMARY OF INVENTION Technical Problem

However, in the above-described configuration, since the cylinder head 518 is formed by the single member, the peripheral wall 525 defining the suction chamber 515 and the peripheral wall 517 defining the discharge chamber 516 are in communication with each other, even though the cooling groove 526 is formed. For this reason, when the peripheral wall 517 is heated by a high-temperature refrigerant gas in the interior of the discharge chamber 516, this heat is transferred from the peripheral wall 517 to the peripheral wall 525, which increases the temperature of the peripheral wall 525. The refrigerant gas suctioned into the suction chamber 515 is also heated. As a result, volumetric efficiency is reduced.

The valve seat plate 514 is provided with the suction port 528. The valve seat plate 514 is also heated by the refrigerant gas in the interior of the discharge chamber 516 and the compressed refrigerant gas in the interior of the cylinder 513. Since the suctioned refrigerant gas is also heated by the heat of the valve seat plate 514, the volumetric efficiency is reduced as in the above case.

The present invention has been made to solve the above described problem, and an object of the present invention is to provide a sealed compressor with high efficiency which is capable of suppressing a temperature increase in a suctioned refrigerant gas to thereby effectively suppress a decrease in volumetric efficiency.

Solution to Problem

To solve the above described problem, the present invention provides a sealed compressor comprising: a sealed container having a sealed space inside thereof; an electric component accommodated in the sealed container; and a compression component accommodated in the sealed container and driven by the electric component to compress a refrigerant gas, wherein the compression component includes: a crankshaft supported such that an axis of the crankshaft extends vertically, the crankshaft being rotated by the electric component; a piston which is provided such that an axis of the piston crosses an axial direction of the crankshaft and is reciprocatable according to a rotation of the crankshaft; a cylinder having a compression chamber inside thereof, the piston being reciprocatably inserted into the cylinder through one end of the cylinder; a valve plate which closes the other end of the cylinder and is provided with a suction hole and a discharge hole; a cylinder head which is fastened to the other end of the cylinder via the valve plate and has a discharge space inside thereof which is in communication with the discharge hole; and a suction muffler which is located below the cylinder, has a muffling space inside thereof, and includes a communication pipe coupled to the suction hole, wherein the communication pipe extends upward from the suction muffler toward the other end of the cylinder and includes a communication pipe exit section at an upper end of the communication pipe such that the communication pipe exit section is in communication with the suction hole, wherein a recess accommodating the communication pipe exit section inside thereof is provided on a lower portion of the cylinder head, and wherein a gas inflow space in an interior of the sealed container is formed between the communication pipe exit section and the recess and is in communication with the sealed space.

The present invention provides a refrigeration device comprising a refrigeration circuit configured such that the sealed compressor having the above configuration, a heat radiator, a pressure-reducing device, and a heat absorbing unit are annularly coupled to each other by use of a pipe.

The above and further objects, features and advantages of the present invention will more fully be apparent from the following detailed description of preferred embodiments with accompanying drawings.

Advantageous Effects of Invention

With the above described configuration, the present invention has an advantage that it is possible to provide a sealed compressor with high efficiency which is capable of suppressing a temperature increase in a suctioned refrigerant gas to effectively suppress a decrease in volumetric efficiency.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic longitudinal sectional view showing a typical example of a sealed compressor according to Embodiment 1 of the present invention.

FIG. 2 is a schematic longitudinal sectional view showing in an enlarged manner the structure surrounded by a dotted line A, in the sealed compressor of FIG. 1.

FIG. 3 is a schematic longitudinal sectional view showing the more specific configuration of a cylinder head of FIG. 2.

FIG. 4 is a schematic plan view showing a state in which the configuration of a cylinder head and the configuration of the exit section of a suction muffler, in the sealed compressor of FIG. 1, when viewed from a block arrow B.

FIG. 5 is a schematic cross-sectional view showing the modified example of the structure surrounded by the dotted line A, in the sealed compressor of FIG. 1.

FIG. 6 is a schematic view showing the basis configuration of a refrigeration device according to Embodiment 2 of the present invention.

FIG. 7 is a longitudinal sectional view showing the exemplary configuration of a region in the vicinity of a cylinder head of a conventional air compressor.

DESCRIPTION OF EMBODIMENTS

The present invention provides a sealed compressor comprising: a sealed container having a sealed space inside thereof; an electric component accommodated in the sealed container; and a compression component accommodated in the sealed container and driven by the electric component to compress a refrigerant gas, wherein the compression component includes: a crankshaft supported such that an axis of the crankshaft extends vertically, the crankshaft being rotated by the electric component; a piston which is provided such that an axis of the piston crosses an axial direction of the crankshaft and is reciprocatable according to a rotation of the crankshaft; a cylinder having a compression chamber inside thereof, the piston being reciprocatably inserted into the cylinder through one end of the cylinder; a valve plate which closes the other end of the cylinder and is provided with a suction hole and a discharge hole; a cylinder head which is fastened to the other end of the cylinder via the valve plate and has a discharge space inside thereof which is in communication with the discharge hole; and a suction muffler which is located below the cylinder, has a muffling space inside thereof, and includes a communication pipe coupled to the suction hole, wherein the communication pipe extends upward from the suction muffler toward the other end of the cylinder and includes a communication pipe exit section at an upper end of the communication pipe such that the communication pipe exit section is in communication with the suction hole, wherein a recess accommodating the communication pipe exit section inside thereof is provided on a lower portion of the cylinder head, and wherein a gas inflow space in an interior of the sealed container is formed between the communication pipe exit section and the recess and is in communication with the sealed space.

In accordance with this configuration, the heat insulating layer which is the gas inflow space in the interior of the sealed container is formed between the communication pipe exit section and the cylinder head. In this structure, it becomes possible to suppress heat transfer from the high-temperature cylinder head to the communication pipe exit section. Because of this, it becomes possible to suppress a temperature increase in the suctioned refrigerant gas flowing through the communication pipe, and to effectively suppress a decrease in the volumetric efficiency of the refrigerant gas. As a result, the efficiency of the sealed compressor can be improved.

In the sealed compressor configured as described above, when the axial direction of the crankshaft is a longitudinal direction and an axial direction of the piston is a lateral direction, the gas inflow space in the interior of the sealed container may include a first space located below the discharge space and extending in the lateral direction to face an upper peripheral surface of the communication pipe exit section, and a second space extending in the longitudinal direction to face a side peripheral surface of the communication pipe exit section, and the first space may have a thickness larger than a thickness of the second space.

In accordance with this configuration, the first space is located in the cylinder head upper section of the cylinder head, including the discharge space, while the second space is located in the cylinder head lower section of the cylinder head. The interior of the discharge space is in a higher-temperature state than the sealed space inside of the sealed container is. In view of this, by setting the thickness of the first space larger than the thickness of the second space, the heat transfer from the discharge space with a large heat amount to the refrigerant gas flowing through the communication pipe can be suppressed. Thus, a temperature increase in the refrigerant gas flowing through the communication pipe can be suppressed more effectively.

In the sealed compressor configured as described above, the communication pipe exit section may have an opening section at a tip end, the opening section being inserted into the suction hole.

In accordance with this configuration, since the opening section is inserted into the suction hole, the refrigerant gas flowing through the communication pipe exit section is suctioned into the compression chamber through the opening section without contacting the valve plate in a high-temperature state. Thus, the gas inflow space in the interior of the sealed container makes it possible to suppress a temperature increase in the refrigerant gas due to the heat transfer from the valve plate as well as a temperature increase in the refrigerant gas.

In the sealed compressor configured as described above, the cylinder head may be formed with a hollow space on a projection plane formed by projecting the suction hole in the lateral direction to the lower portion of the cylinder head.

In accordance with this configuration, between the cylinder head and the communication pipe exit section, a space defined by the hollow space as well as the gas inflow space in the interior of the sealed container is formed. This makes it possible to further suppress the heat transfer from the cylinder head in a high-temperature state to the communication pipe exit section.

In the sealed compressor configured as described above, the communication pipe exit section may be provided with a heat insulating space isolated from the sealed space, on an outer periphery facing the valve plate, and a communication hole which provides communication between the heat insulating space and an interior of the communication pipe exit section.

In accordance with this configuration, the heat insulating space into which the refrigerant gas is introduced is formed between the communication pipe exit section and the valve plate. This makes it possible to keep the temperature of the heat insulating space at a value which is substantially equal to that of the refrigerant gas. In this way, the heat transfer from the valve plate to the communication pipe exit section can be further suppressed.

In the sealed compressor configured as described above, the suction muffler may be molded by use of a resin, and the heat insulating space may be formed integrally with the suction muffler, when the suction muffler is molded.

In accordance with this configuration, the heat insulating space is formed integrally as a part of the shape of the communication pipe when the suction muffler is molded by use of a resin. This allows the heat insulating space to more effectively perform heat insulation.

The sealed compressor may be configured to be driven at one of a plurality of operating frequencies.

In accordance with this configuration, since the gas inflow space in the interior of the sealed container can suppress the heat transfer to the communication pipe exit section, a temperature increase in the refrigerant gas flowing through the communication pipe can be suppressed effectively, even when the refrigerant gas is flowing through the communication pipe at a low velocity. Therefore, even in the case of using the operating frequency at which the sealed compressor is inverter-driven by a low-speed rotation in which the flow velocity of the refrigerant gas is low, the efficiency of the sealed compressor can be improved.

The present invention also provides a refrigeration device comprising a refrigeration circuit configured such that the sealed compressor having the above configuration, a heat radiator, a pressure-reducing device, and a heat absorbing unit are annularly coupled to each other by use of a pipe.

In accordance with this configuration, since the refrigeration device includes the refrigeration circuit incorporating the sealed compressor having the above configuration, the refrigeration device is able to reduce electric power consumption and realize energy saving.

Hereinafter, the preferred embodiment of the present invention will be described with reference to the drawings. Throughout the drawings, the same or corresponding components are identified by the same reference symbols, and will not be described repeatedly.

Embodiment 1

[Exemplary Configuration of Sealed Compressor]

Initially, the exemplary configuration of the sealed compressor according to the present embodiment will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, a sealed compressor 100 according to the present embodiment includes an electric component 120 and a compression component 130 which are accommodated in a sealed container 101, and the sealed container 101 is filled with, for example, a refrigerant gas and lubricating oil 103. The electric component 120 and the compression component 130 constitute a compressor body. The compressor body is placed inside of the sealed container 101 such that the compressor body is elastically supported by a suspension spring 102 provided in the bottom portion of the sealed container 101.

The sealed container 101 is provided with a suction pipe 104 and a discharge pipe 105. One end of the suction pipe 104 is in communication with the inner space of the sealed container 101, while the other end thereof is connected to a refrigeration device which is not shown, thus constituting a refrigeration cycle. One end of the discharge pipe 105 is connected to the compression component 130, while the other end thereof is connected to a refrigeration device which is not shown. As will be described later, the refrigerant gas compressed by the compression component 130 is guided to the refrigeration cycle through the discharge pipe 105, and the refrigerant gas from the refrigeration cycle is guided to the inner space of the sealed container 101 via the suction pipe 104.

The specific configuration of the sealed container 101 is not particularly limited. In the present embodiment, for example, the sealed container 101 is manufactured by a drawing process of an iron plate. The refrigerant gas is filled in the sealed container 101 under a pressure equal to a pressure at a lower-pressure side in the refrigeration cycle into which the sealed compressor 100 is incorporated, and at a relatively low temperature. The lubricating oil 103 is filled to lubricate a crankshaft 140 (which will be described later) included in the compression component 130. As shown in FIG. 1, the lubricating oil 103 is reserved in the bottom portion of the sealed container 101.

The kind of the refrigerant gas is not particularly limited, and a gas known in the field of the refrigeration cycle is suitably used. In the present embodiment, for example, hydrocarbon-based refrigerant gas such as R600a is suitably used. R600a has a low global warming potential and is one of refrigerant gases favorably used in terms of global environment conservation. In addition, the kind of the lubricating oil 103 is not particularly limited, and lubricating oil known in the fields of the compressor may be suitably used.

As shown in FIG. 1, the electric component 120 includes at least a stator 121 and a rotor 122. The stator 121 is fastened to the lower side of a cylinder block 131 (which will be described later) included in the compression component 130 by use of a fastening member such as a bolt. The rotor 122 is placed coaxially with the stator 121 in a location inward of the stator 121. A main shaft 142 of a crankshaft 140 (which will be described later) included in the compression component 130, is fastened to the rotor 122, by, for example, shrink-fitting. The electric component 120 is connected to an external inverter driving circuit (not shown) and inverter-driven at one of a plurality of frequencies.

The compression component 130 is driven by the electric component 120 and compresses the refrigerant gas. As shown in FIG. 1, the compression component 130 includes a cylinder block 131, a piston 132, a cylinder 133, a compression chamber 134, a bearing section 135, a coupling section 136, a crankshaft 140, a valve plate 151, a cylinder head 152, a suction valve 153, a suction muffler 160, and others.

The cylinder block 131 is provided with the cylinder 133 and the bearing section 135. When a vertical direction is a longitudinal direction and a horizontal direction is a lateral direction, in a state in which the sealed compressor 100 is placed on a horizontal plane, the cylinder 133 is placed along the lateral direction and fastened to the bearing section 135 in the interior of the sealed container 101. The cylinder 133 is formed with a bore of a substantially cylindrical shape with a diameter substantially equal to that of the piston 132. The piston 132 is reciprocatably inserted into the cylinder 133. The cylinder 133 and the piston 132 define the compression chamber 134, and the refrigerant gas is compressed in the interior of the compression chamber 134. The bearing section 135 supports the main shaft 142 of the crankshaft 140 such that the main shaft 142 is rotatable.

The crankshaft 140 is supported in the interior of the sealed container 101 in such a manner that its axis (axis of the crankshaft 140) extends in the longitudinal direction. The crankshaft 140 includes the main shaft 142, an eccentric shaft 141, an oil feeding mechanism 143, and others. As described above, the main shaft 142 is fastened to the rotor 122 of the electric component 120. The eccentric shaft 141 is configured to be eccentric with respect to the main shaft 142. The oil feeding mechanism 143 is provided so as to provide communication between the lower end of the main shaft 142 immersed in the lubricating oil 103 and the upper end of the eccentric shaft 141. The oil feeding mechanism 143 includes an oil feeding pump, a spiral channel formed on the surface of the main shaft 142, etc. The oil feeding mechanism 143 feeds the lubricating oil 103 to the crankshaft 140.

The piston 132 inserted into the cylinder 133 is coupled to the coupling section 136. The piston 132 is placed such that its axis crosses the axial direction of the crankshaft 140. In the present embodiment, as shown in FIG. 2, the crankshaft 140 is placed such that its center axis extends in the longitudinal direction, while the piston 132 is placed such that its center axis extends in the lateral direction. Therefore, the axial direction of the piston 132 is perpendicular to the axial direction of the crankshaft 140. The coupling section 136 is coupled to the piston 132 and to the eccentric shaft 141 of the crankshaft 140. The coupling section 136 transmits the rotational motion of the crankshaft 140 rotated by the electric component 120 to the piston 132, and thereby the piston 132 reciprocates in the interior of the cylinder 133.

As described above, the piston 132 is inserted into one end portion (closer to the crankshaft 140) of the cylinder 133. The other end portion (end portion which is away from the crankshaft 140) of the cylinder 133 is closed by a valve plate 151 and the cylinder head 152. The cylinder head 152 is fastened together with the valve plate 151 to the cylinder 133 by use of a fastening member such as a head bolt. The valve plate 151 is placed between the cylinder 133 and the cylinder head 152. As shown in FIG. 2, the valve plate 151 is formed with a suction hole 151 a and a discharge hole 151 b.

The cylinder head 152 is divided into a cylinder head upper section 152-1 and a cylinder head lower section 152-2 by a lateral broken line C of FIGS. 2, 3, and 4. This broken line C is on the basis of the upper end of a gas inflow space 152 b in the interior of the sealed container, which will be described later. The cylinder head upper section 152-1 has a casing shape in which a discharge space 152 a is formed inside thereof. The cylinder head lower section 152-2 is formed with a recess 152 d in which the upper end (communication pipe exit section 162 a) of a communication pipe 162 of the suction muffler 160 can be placed. For easier explanation of the description, the recess 152 d is surrounded by a broken-line area in FIG. 2, while the recess 152 d is indicated by an arrow in FIGS. 3 and 4.

Hereinafter, for easier description, the surface (surface closer to the compression chamber 134 and closer to the cylinder 133) of the cylinder head 152 which contacts the valve plate 151 will be referred to as a “contact surface 152 p” and a surface which is on an opposite side of the contact surface 152 p will be referred to as “non-contact surface 152 q”. As shown in FIG. 3, the discharge space 152 a of the cylinder head 152 is opened in the contact surface 152 p and closed by the non-contact surface 152 q. As shown in FIG. 4, the contact surface 152 p is a flat surface positioned in the vicinity of the opening of the discharge space 152 a. As shown in FIG. 2, the contact surface 152 p contacts the valve plate 151 and thus the discharge space 152 a is sealingly closed.

As described above, the contact surface 152 p is the flat surface. The non-contact surface 152 q is also present in the cylinder head lower section 152-2. The upper portion of the non-contact surface 152 q is a curved surface 152 q-1 protruding downward from the upper side of FIG. 3. The lower portion of the non-contact surface 152 q includes a first flat surface 152 q-2 which is substantially flat and extends vertically downward to be below the discharge space 152 a and a second flat surface 152 q-3 which is substantially flat and is located inward relative to the first flat surface 152 q-2. In brief, as shown in FIG. 3, the non-contact surface 152 q includes the curved surface 152 q-1, the first flat surface 152 q-2, and the second flat surface 152 q-3.

The inner surface of the recess 152 d of the cylinder head lower section 152-2 is a curved surface conforming in shape to the communication pipe exit section 162 a. In other words, the inner surface of the recess 152 d of the cylinder head lower section 152-2 faces the outer surface of the communication pipe exit section 162 a. Hereinafter, the surface facing the outer surface of the communication pipe exit section 162 a will be referred to as “opposed surface 152 r” for easier description. As shown in FIGS. 2 and 4, the gas inflow space 152 b in the interior of the sealed container, which will be described later, is formed between the communication pipe exit section 162 a and the opposed surface 152 r. In addition, as shown in FIGS. 2 and 4, a heat insulating space 162 c which will be described later is formed between the valve plate 151 and the communication pipe exit section 162 a. Further, as shown in FIGS. 2, 3, and 4, the cylinder head lower section 152-2 is formed with a hollow space 152 c (which will be described later) extending from the side of the non-contact surface 152 q toward the gas inflow space 152 b in the interior of the sealed container (recess 152 d) such that the hollow space 152 c is in communication with the gas inflow space 152 b in the interior of the sealed container.

The suction hole 151 a provides communication between the communication pipe 162 (the communication pipe exit section 162 a) of the suction muffler 160 and the compression chamber 134. A suction valve 153 for opening and closing the suction hole 151 a is provided on the surface of the valve plate 151 which is closer to the compression chamber 134. The suction hole 151 a can be opened and closed by the suction valve 153. The refrigerant gas is suctioned from the suction muffler 160 into the compression chamber 134, via the suction hole 151 a, when the suction valve 153 is opened.

The discharge hole 151 b provides communication between the cylinder head 152 and the compression chamber 134. The discharge hole 151 b is opened and closed by a discharge valve (not shown). The cylinder head 152 is formed with the discharge space 152 a inside thereof. The refrigerant gas is discharged from the compression chamber 134 to the discharge space 152 a through the discharge hole 151 b. The discharge pipe 154 is coupled to the cylinder head 152 and to a discharge pipe 105. Therefore, the discharge space 152 a is in communication with the discharge pipe 105 via the discharge pipe 154. The suction muffler 160 is located at a lower side in the interior of sealed container 101, from the perspective of the cylinder 133 and the cylinder head 152. The suction muffler 160 is made of, for example, a composite material comprising a resin such as PBT (polybuthylene terephthalate) and reinforced fibers such as glass fibers added to the resin. The suction muffler 160 includes a tail pipe 161, the communication pipe 162, a muffler body 163, and others. The material of the suction muffler 160 is not limited to the composite material containing the PBT so long as the suction muffler 160 is molded by use of least a resin.

A muffling space 163 a of the suction muffler 160 is formed by the muffler body 163. The tail pipe 161 is in communication with the internal space of the sealed container 101, and serves to guide the refrigerant gas to the interior of the muffler body 163. The communication pipe 162 is located at the upper side of the muffler body 163. The communication pipe 162 is in communication with the compression chamber 134 via the suction hole 151 a of the valve plate 151. The communication pipe 162 guides the refrigerant gas from the interior of the muffler body 163 to the interior of the compression chamber 134.

The communication pipe 162 of the suction muffler 160 extends upward toward the other end portion (end portion which is away from the crankshaft 140) of the cylinder 133, in a location between the valve plate 151 and the cylinder head 152. As shown in FIGS. 2 and 3, the upper end of the communication pipe 162 is provided with the communication pipe exit section 162 a.

As described above, the cylinder head 152 is provided with the recess 152 d in a location that is closer to the compression chamber 134. The communication pipe exit section 162 a is inserted into the recess 152 d such that a specified space (the gas inflow space 152 b in the interior of the sealed container) is formed between the communication pipe exit section 162 a and the opposed surface 152 r (inner surface of the recess 152 d). For example, an elastic member (not shown) is placed inside of the recess 152 d. This elastic member presses the communication pipe exit section 162 a against the valve plate 151, and thus the communication pipe exit section 162 a is retained between the elastic member and the valve plate 151.

An opening section 162 b is provided at the tip end of the communication pipe exit section 162 a. The opening section 162 b is in communication with the suction hole 151 a of the valve plate 151. The state in which the opening section 162 b and the suction hole 151 a are in communication with each other is not particularly limited. In the present embodiment, as shown in FIG. 2, the opening section 162 b protrudes from the communication pipe exit section 162 a and is inserted into the suction hole 151 a. In this structure, the opening section 162 b does not contact the surface of the valve plate 151 which is closer to the cylinder head 152, but is inserted into the suction hole 151 a and exposed at the surface which is closer to the cylinder 133.

Since the opening section 162 b of the communication pipe exit section 162 a and the suction hole 151 a are in communication with each other as described above, the communication pipe 162 and the compression chamber 134 are in communication with each other via the suction hole 151 a (and the suction valve 153). Therefore, the suction muffler 160 is in communication with the compression chamber 134 inside of the cylinder 133 via the communication pipe 162, and the upper end (the communication pipe exit section 162 a) of the communication pipe 162 is placed in a biased manner inside of the recess 152 d of the cylinder head 152. In this way, the suction muffler 160 is fastened to the valve plate 151.

[Operation of Sealed Compressor]

Next, the operation and advantages of the sealed compressor 100 configured as described above will be specifically described. Although not shown in FIGS. 1 to 4, the sealed compressor 100 is incorporated into the refrigeration cycle in such a manner that the suction pipe 104 and the discharge pipe 105 are connected to the refrigeration device having a well-known configuration.

Initially, when the electric component 120 is applied with a current from an external electric power supply, the current flows through the stator 121, to generate a magnetic field, causing the rotor 122 to rotate. According to the rotation of the rotor 122, the main shaft 142 of the crankshaft 140 rotates, and then the rotational motion of the main shaft 142 is transmitted to the piston 132 via the eccentric shaft 141 and the coupling section 136. The piston 132 reciprocates in the interior of the cylinder 133. According to the reciprocation motion of the piston 132, the refrigerant gas is suctioned, compressed and discharged in the interior of the compression chamber 134.

This will be described more specifically. Now, of the direction in which the piston 132 moves in the interior of the cylinder 133, a direction in which the volume of the compression chamber 134 increases will be referred to as “increase direction” and a direction in which the volume of the compression chamber 134 decreases will be referred to as “decrease direction”. When the piston 132 moves in the increase direction, the refrigerant gas in the interior of the compression chamber 134 expands. When a pressure in the interior of the compression chamber 134 falls below a suction pressure, the suction valve 153 starts to open due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the suction muffler 160.

According to this operation, the low-temperature refrigerant gas which has returned from the refrigeration device is released to the interior of the sealed container 101 from the suction pipe 104. Then, the refrigerant gas is suctioned from a suction port (not shown) provided on the suction muffler 160 and introduced to the interior of the muffling space 163 a of the muffler body 163 via the tail pipe 161. At this time, since the suction valve 153 starts to open as described above, the introduced refrigerant gas flows into the compression chamber 134 through the communication pipe 162 and the suction hole 151 a. After that, when the piston 132 moves from a bottom dead center in the decrease direction in the interior of the cylinder 133, the refrigerant gas is compressed in the interior of the compression chamber 134, so that the pressure in the interior of the compression chamber 134 increases. In addition, due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the suction muffler 160, the suction valve 153 is closed.

Then, when the pressure in the interior of the compression chamber 134 exceeds the pressure in the interior of the discharge space 152 a, the discharge valve (not shown) starts to open, due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the discharge space 152 a.

According to this operation, during a period that passes until the piston 132 reaches a top dead center in the interior of the cylinder 133, the compressed refrigerant gas is discharged to the discharge space 152 a through the discharge hole 151 b. The refrigerant gas discharged to the discharge space 152 a is sent out to the refrigeration device via the discharge pipe 154 and the discharge pipe 105.

After that, when the piston 132 moves again in the increase direction from the top dead center in the interior of the cylinder 133, the refrigerant gas in the interior of the compression chamber 134 expands, so that the pressure in the interior of the compression chamber 134 decreases. When the pressure in the interior of the compression chamber 134 falls below the pressure in the interior of the discharge space 152 a, the discharge valve is closed.

The above described suction stroke, compression stroke and discharge stroke are repeatedly performed in every rotation of the crankshaft 140, and thus the refrigerant gas is circulated within the refrigeration cycle.

[Configuration of Cylinder Head and Configuration of Communication Pipe Exit Section]

Next, the gas inflow space 152 b in the interior of the sealed container (gas inflow space 152 b), which is defined by the cylinder head 152 and the communication pipe exit section 162 a, will be specifically described with reference to FIGS. 2 to 4.

As shown in FIGS. 2 and 4, in the recess 152 d of the cylinder head 152, the gas inflow space 152 b is formed between the opposed surface 152 r (see FIG. 3) and the communication pipe exit section 162 a. The gas inflow space 152 b includes a first space 152 b-1 as a lateral space and a second space 152 b-2 as a longitudinal space.

The first space 152 b-1 is formed between the lower surface of the cylinder head 152 inside of the recess 152 d and the upper peripheral surface of the communication pipe exit section 162 a. The lower surface of the cylinder head 152 inside of the recess 152 d corresponds to a curved surface (upper curved surface of the recess 152 d) of the opposed surface 152 r of the recess 152 d, which is closer to the discharge space 152 a. The second space 152 b-2 is formed between the side surface of the cylinder head 152 inside of the recess 152 d and the side peripheral surface of the communication pipe exit section 162 a. The side surface of the cylinder head 152 inside of the recess 152 d corresponds to the inner peripheral curved surface of the opposed surface 152 r of the recess 152 d, which is other than the upper curved surface. The first space 152 b-1 and the second space 152 b-2 constitute a continuous one space formed around the communication pipe exit section 162 a, i.e., the gas inflow space 152 b. The first space 152 b-1 and the second space 152 b-2 are in communication with the sealed space in the interior of the sealed container 101.

Since the first space 152 b-1 is the lateral space of the gas inflow space 152 b, the first space 152 b-1 is regarded as the space extending along the axial direction of the piston 132 so as to face the upper peripheral surface of the communication pipe exit section 162 a. In contrast, since the second space 152 b-2 is the longitudinal space of the gas inflow space 152 b, the second space 152 b-2 is regarded as the space extending along the axial direction of the crankshaft 140 so as to face the side peripheral surface of the communication pipe exit section 162 a. As shown in FIG. 2, the gas inflow space 152 b is configured in such a manner that a thickness W1 of the first space 152 b-1 is larger than a thickness W2 of the second space 152 b-2.

The thickness W1 of the first space 152 b-1 is set to the average value of the lengths of a plurality of perpendicular lines which are drawn from the upper curved surface of the recess 152 d to the upper peripheral surface of the communication pipe exit section 162 a. Also, the thickness W2 of the second space 152 b-2 is set to the average value of the lengths of a plurality of perpendicular lines which are drawn from the inner peripheral curved surface of the recess 152 d to the side peripheral surface of the communication pipe exit section 162 a.

Further, in the present embodiment, as shown in FIGS. 2, 3, and 4, the cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152 c. As indicated by a dotted line of FIG. 4, the hollow space 152 c is formed in a location obtained by projecting the opening section 162 b of the communication pipe exit section 162 a to the cylinder head lower section 152-2. As shown in FIG. 2, the opening section 162 b is placed in communication with the suction hole 151 a of the valve plate 151. Therefore, the hollow space 152 c is formed in the location (on a projection plane) obtained by projecting the suction hole 151 a to the cylinder head lower section 152-2.

As shown in FIGS. 2 and 3, the hollow space 152 c is provided to extend along the axial direction of the piston 132, in the cylinder head lower section 152-2, and therefore constitutes an opening which is in communication with the second space 152 b-2 of the gas inflow space 152 b. As shown in FIG. 4, the opening of the hollow space 152 c preferably includes the opening section 162 b of the communication pipe exit section 162 a. Therefore, the size of the opening of the hollow space 152 c is preferably larger than the area of the opening section 162 b and the area of the corresponding suction hole 151 a. Although in the example of FIG. 4, the opening of the hollow space 152 c has a laterally elongated shape, the shape of the opening of the hollow space 152 c is not limited to this.

In addition to the above, in the present embodiment, as shown in FIGS. 2 and 4, the heat insulating space 162 c is formed on the outer periphery of the communication pipe exit section 162 a, which is immediately below the opening section 162 b (the outer periphery of the communication pipe exit section 162 a, which faces the valve plate 151). Since the heat insulating space 162 c is formed as a recess in the outer periphery of the communication pipe exit section 162 a, this recess may be formed integrally on the outer periphery of the communication pipe exit section 162 a when the suction muffler 160 is molded, for example. Further, the recess may be processed after the suction muffler 160 is molded. Preferably, the recess is molded integrally with the suction muffler 160, when the suction muffler 160 is molded.

The interior of the heat insulating space 162 c and the interior of the communication pipe 162 are in communication with each other via a communication hole 162 d. In other words, on the outer periphery of the communication pipe exit section 162 a, which is immediately below the opening section 162 b, the heat insulating space 162 c and the communication hole 162 d penetrating the communication pipe 162 are formed. As shown in FIGS. 2 and 4, the heat insulating space 162 c is formed as the recess which opens toward the valve plate 151. Since the communication pipe exit section 162 a is in contact with the valve plate 151, the heat insulating space 162 c is a sealed space isolated from the surrounding sealed space and the gas inflow space 152 b. The refrigerant gas inside of the communication pipe 162 is introduced into the heat insulating space 162 c via the communication hole 162 d, and does not leak from the heat insulating space 162 c.

The advantage attained by suppressing a temperature increase in the suctioned refrigerant gas and effectively suppressing a decrease in the volumetric efficiency, which is associated with the gas inflow space 152 b, will be now described.

The cylinder head 152 and the valve plate 151 which is in sealing contact with the cylinder head 152 are heated by the high-temperature refrigerant gas in the interior of the discharge space 152 a and raised in temperature. In addition, the valve plate 151 is also heated by the compressed refrigerant gas in the interior of the compression chamber 134 and raised in temperature. In a sealed compressor having a typical configuration, the refrigerant gas suctioned into the suction muffler 160 is heated and its volume is increased by the valve plate 151, while the refrigerant gas is flowing from the communication pipe exit section 162 a and through the suction hole 151 a of the valve plate 151. For this reason, in the conventional sealed compressor, the volumetric efficiency is decreased.

In contrast, in the present embodiment, since the gas inflow space 152 b in the interior of the sealed container is formed between the communication pipe exit section 162 a and the cylinder head 152, the gas inflow space 152 b becomes a heat insulating layer which can suppress heat transfer from the high-temperature cylinder head 152 to the communication pipe exit section 162 a. Since heating of the refrigerant gas can be suppressed effectively when the refrigerant gas is suctioned into the compression chamber 134, the volumetric efficiency of the sealed compressor 100 can be increased.

The space temperatures will now be described. The temperature of the discharge space 152 a inside of the cylinder head 152 is the highest, and the temperature of the inner space of the sealed container 101 is higher than the temperature of the interior of the communication pipe 162 of the suction muffler 160. In order to suppress heat transfer to the refrigerant gas flowing through the communication pipe 162 (especially the communication pipe exit section 162 a), the gas inflow space 152 b is configured in such a manner that the thickness W1 of the first space 152 b-1 extending along the axial direction (lateral direction) of the piston 132 is set larger than the thickness W2 of the second space 152 b-2 extending along the axial direction (longitudinal direction) of the crankshaft 140. In other words, by setting the thickness W1 of the first space 152 b-1 located below the discharge space 152 a larger than the thickness W2 of the second space 152 b-2, it becomes possible to effectively suppress the heat transfer from the discharge space 152 a with a large heat amount to the communication pipe exit section 162 a.

As shown in FIG. 2, in the present embodiment, the opening section 162 b at the tip end of the communication pipe exit section 162 a protrudes and is inserted into the suction hole 151 a. This makes it possible to avoid a situation in which the low-temperature refrigerant gas directly contacts the high-temperature valve plate 151 when the refrigerant gas flowing through the communication pipe 162 is suctioned into the compression chamber 134.

In accordance with the present embodiment, the second space 152 b-2 of the gas inflow space 152 b suppresses the heat transfer from the cylinder head lower section 152-2 of the cylinder head 152 to the refrigerant gas flowing through the communication pipe exit section 162 a, while the first space 152 b-1 of the gas inflow space 152 b suppresses the heat transfer from the discharge space 152 a inside of the cylinder head upper section 152-1 to the refrigerant gas flowing through the communication pipe exit section 162 a. Because of this, it becomes possible to effectively suppress a temperature increase in the refrigerant gas suctioned from the opening section 162 b to the interior of the compression chamber 134 via the suction hole 151 a. In addition, as described above, the opening section 162 b inserted into the suction hole 151 a also serves as the heat insulating layer. Since it becomes possible to suppress the heat transfer from the high-temperature valve plate 151 to the refrigerant gas which has been suppressed in temperature increase, the low-temperature refrigerant gas which has been suppressed in temperature increase can be suctioned into the compression chamber 134.

The cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152 c with a size including the opening area of the suction hole 151 a, on the lateral projection plane of the suction hole 151 a. In this structure, a portion of the high-temperature cylinder head 152 (cylinder head lower section 152-2) does not exist in the lateral direction, from the perspective of the opening section 162 b of the communication pipe exit section 162 a. Further, the second space 152 b-2 of the gas inflow space 152 b is formed between the communication pipe exit section 162 a and the cylinder head lower section 152-2, while the first space 152 b-1 of the gas inflow space 152 b is formed between the communication pipe exit section 162 a and the cylinder head upper section 152-1. This structure can reduce the area of a portion of the cylinder head 152 and a portion of the communication pipe exit section 162 a, which overlap with each other, with the gas inflow space 152 b located between the cylinder head 152 and the communication pipe exit section 162 a. As a result, it becomes possible to more effectively suppress the heat transfer from the high-temperature cylinder head 152 to the communication pipe exit section 162 a, and more effectively suppress a temperature increase in the refrigerant gas.

Further, the communication pipe exit section 162 a is formed with the heat insulating space 162 c isolated from the sealed space, on the outer periphery immediately below the opening section 162 b. As described above, the heat insulating space 162 c is formed integrally when the suction muffler 160 is manufactured by molding. The refrigerant gas is introduced into the heat insulating space 162 c through the communication hole 162 d. Therefore, the heat insulating space 162 c can be kept at a low temperature which is close to the temperature of the refrigerant gas by the low-temperature refrigerant gas introduced thereinto. In this way, it becomes possible to provide heat insulation between the outer periphery of the communication pipe exit section 162 a which is closer to the valve plate 151 and the valve plate 151. Thus, the communication pipe exit section 162 a can be thermally insulated from the cylinder head 152 by the gas inflow space 152 b and further thermally insulated by the heat insulating space 162 c. As a result, it becomes possible to more effectively suppress a temperature increase in the refrigerant gas flowing through the communication pipe exit section 162 a.

As described above, in the present embodiment, since at least the gas inflow space 152 b in the interior of the sealed container is formed, the heat transfer from the cylinder head 152 to the communication pipe exit section 162 a can be suppressed. In addition, since the cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152 c, the heat transfer to the communication pipe exit section 162 a can be suppressed more effectively. Further, since the opening section 162 b of the communication pipe exit section 162 a is inserted into the suction hole 151 a, the heat transfer from the valve plate 151 to the refrigerant gas inside of the opening section 162 b can be suppressed. Since the heat insulating space 162 c is provided immediately below the opening section 162 b of the communication pipe exit section 162 a, the heat transfer from the valve plate 151 to the communication pipe exit section 162 a can be suppressed more effectively. Because of the above, in accordance with the present embodiment, it becomes possible to effectively suppress a temperature increase in the suctioned refrigerant gas, flowing though the communication pipe 162. As a result, the volumetric efficiency can be increased, and hence the efficiency of the sealed compressor 100 can be increased.

Modified Example

Although in the present embodiment, the operating frequency of the sealed compressor 100 is not particularly limited, the sealed compressor 100 may be configured to be inverter-driven at one of a plurality of operating frequencies. As described above, in the present embodiment, since at least the gas inflow space 152 b in the interior of the sealing container is formed, the heat transfer from the cylinder head 152 and the valve plate 151 which are in high-temperature states to the refrigerant gas flowing through the communication pipe exit section 162 a can be suppressed. In this configuration, even when the refrigerant gas flows through the communication pipe 162 at a relatively low velocity, the heat transfer from the cylinder head 152 and the valve plate 151 to the refrigerant gas can be suppressed effectively. Therefore, the sealed compressor 100 can be inverter-driven to rotate at a low speed.

In the present embodiment, the gas inflow space 152 b includes the first space 152 b-1 extending in the lateral direction (axial direction of the piston 132) and having the curved cross-section and the second space 152 b-2 extending in the longitudinal direction (axial direction of the crankshaft 140) and having the curved cross-section. However, the configuration of the gas inflow space 152 b is not limited to this, and may include the first space 152 b-1 and the second space 152 b-2, depending on the specific configuration of the sealed compressor 100.

The first space 152 b-1 of the gas inflow space 152 b thermally insulates the upper peripheral surface of the communication pipe exit section 162 a, while the second space 152 b-2 of the gas inflow space 152 b thermally insulates the side peripheral surface of the communication pipe exit section 162 a which is other than the location facing the valve plate 151. Alternatively, the sealed compressor 100 may include a space which thermally insulates another peripheral surface of the communication pipe exit section 162 a or a space which thermally insulates the peripheral surface of a portion of the communication pipe 162 which is other than the communication pipe exit section 162 a, depending on the configuration of the sealed compressor 100.

Although in the present embodiment, the cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152 c, the cylinder head lower section 152-2 may not be formed with the hollow space 152 c, as shown in FIG. 5. In this case, the thickness W2 of the second space 152 b-2 may be set larger than in a case where the cylinder head lower section 152-2 is formed with the hollow space 152 c (configuration of FIG. 2). Therefore, in the gas inflow space 152 b, the thickness W1 of the first space 152 b-1 which is located closer to the discharge space 152 a in a higher-temperature state is preferably larger than the thickness W2 of the second space 152 b-2. However, depending on the specific configuration of the sealed compressor 100, the thickness W1 of the first space 152 b-1 may be equal to the thickness W2 of the second space 152 b-2, or the thickness W2 of the second space 152 b-2 may be larger the thickness W1 of the first space 152 b-1.

Further, a known spacer may be provided between the communication pipe exit section 162 a and the recess 152 d of the cylinder head 152, to suitably maintain the thickness W1 and the thickness W2 of the gas inflow space 152 b. This spacer may have a low heat conductivity and have a stiffness which can maintain the shape between the opposed surface 152 r of the recess 152 d, facing the outer surface of the communication pipe exit section 162 a, and the outer peripheral surface of the communication pipe exit section 162 a.

Embodiment 2

In Embodiment 2, an exemplary refrigeration device including the sealed compressor 100 described in Embodiment 1 will be described specifically with reference to FIG. 6.

The sealed compressor 100 of the present invention can be suitably incorporated into a refrigeration cycle or various devices (refrigeration devices) having a configuration similar to that of the refrigeration cycle. Specifically, for example, the devices may be a refrigerator (refrigerator for household use or refrigerator for business purpose), an ice making machine, a show case, a dehumidifier, a heat pump type hot water supply device, a heat pump type laundry/drying machine, an automatic vending machine, an air conditioner, an air compressor, etc. However, these are merely exemplary. In the present embodiment, the basic configuration of a refrigeration device 200 will be described in conjunction with an article storage device of FIG. 6, as an exemplary device into which of the sealed compressor 100 of the present invention is incorporated.

The refrigeration device 200 of FIG. 6 includes a refrigeration device body 201 and a refrigeration circuit 205. The refrigeration device body 201 includes a heat insulating casing having an opening and a door which opens and closes the opening of the casing. The refrigeration device body 201 includes in the interior thereof a storage space 202 storing articles, a mechanical room 203 storing the refrigerant circuit 205 and the like, and a partition wall 204 which defines the storage space 202 and the mechanical room 203.

The refrigeration circuit 205 is configured such that the sealed compressor 100 of Embodiment 1, a heat radiator 206, a pressure-reducing device 207, and a heat absorbing unit 208 are connected together in an annular shape by use of a pipe 209. In brief, the refrigeration circuit 205 is an exemplary refrigeration cycle using the sealed compressor 100 of the present invention.

In the refrigeration circuit 205, the sealed compressor 100, the heat radiator 206, and the pressure-reducing device 207 are placed in the mechanical room 203, while the heat absorbing unit 208 is placed in the storage space 202 including a blower (not shown in FIG. 6). As indicated by a broken line arrow, the blower agitates cooling heat of the heat absorbing unit 208 to circulate the cooling heat in the interior of the storage space 202.

As described above, the refrigeration device 200 of the present embodiment incorporates the sealed compressor 100 of Embodiment 1. As described above, since the sealed compressor 100 includes the gas inflow space 152 b in the interior of the sealed container, a decrease in the volumetric efficiency can be suppressed effectively by suppressing a temperature increase in the refrigerant gas. Thus, the efficiency of the sealed compressor 100 is high. By operating the refrigeration circuit 205 by use of the sealed compressor 100 with such high efficiency, electric consumption in the refrigeration device 200 can be reduced, and hence energy saving can be realized.

Numerous improvements and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, the description is to be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and/or function may be varied substantially without departing from the spirit of the invention.

INDUSTRIAL APPLICABILITY

The present invention can increase the efficiency of a sealed compressor, and therefore is suitably used in the fields of the sealed compressor. For example, the present invention can be widely suitably used in the fields of refrigeration devices including sealed compressors, such as refrigeration devices for household uses such as electric freezers/refrigerators or air conditioners, or refrigeration devices for business purposes such as a show case for business purpose or an automatic vending machine, etc.

REFERENCE SIGNS LIST

-   100 sealed compressor -   101 sealed container -   104 suction pipe -   105 discharge pipe -   120 electric component -   130 compression component -   131 cylinder block -   132 piston -   133 cylinder -   134 compression chamber -   136 coupling section -   140 crankshaft -   141 eccentric shaft -   142 main shaft -   151 valve plate -   151 a suction hole -   151 b discharge hole -   152 cylinder head -   152-1 cylinder head upper section -   152-2 cylinder head lower section -   152 a discharge space -   152 b gas inflow space in interior of sealed container -   152 c hollow space -   152 d recess -   153 suction valve -   154 discharge pipe -   160 suction muffler -   161 tail pipe -   162 communication pipe -   162 a communication pipe exit section -   162 b opening section -   162 c heat insulating space -   163 muffler body -   163 a muffling space -   200 refrigeration device -   205 refrigeration circuit -   206 heat radiator -   207 pressure-reducing device -   208 heat absorbing unit 

1. A sealed compressor comprising: a sealed container having a sealed space inside thereof; an electric component accommodated in the sealed container; and a compression component accommodated in the sealed container and driven by the electric component to compress a refrigerant gas, wherein the compression component includes: a crankshaft supported such that an axis of the crankshaft extends vertically, the crankshaft being rotated by the electric component; a piston which is provided such that an axis of the piston crosses an axial direction of the crankshaft and is reciprocatable according to a rotation of the crankshaft; a cylinder having a compression chamber inside thereof, the piston being reciprocatably inserted into the cylinder through one end of the cylinder; a valve plate which closes the other end of the cylinder and is provided with a suction hole and a discharge hole; a cylinder head which is fastened to the other end of the cylinder via the valve plate and has a discharge space inside thereof which is in communication with the discharge hole; and a suction muffler which is located below the cylinder, has a muffling space inside thereof, and includes a communication pipe coupled to the suction hole, wherein the communication pipe extends upward from the suction muffler toward the other end of the cylinder and includes a communication pipe exit section at an upper end of the communication pipe such that the communication pipe exit section is in communication with the suction hole, wherein a recess accommodating the communication pipe exit section inside thereof is provided on a lower portion of the cylinder head, and wherein a gas inflow space in an interior of the sealed container is formed between the communication pipe exit section and the recess and is in communication with the sealed space.
 2. The sealed compressor according to claim 1, wherein when the axial direction of the crankshaft is a longitudinal direction and an axial direction of the piston is a lateral direction, the gas inflow space in the interior of the sealed container includes a first space located below the discharge space and extending in the lateral direction to face an upper peripheral surface of the communication pipe exit section, and a second space extending in the longitudinal direction to face a side peripheral surface of the communication pipe exit section, and wherein the first space has a thickness larger than a thickness of the second space.
 3. The sealed compressor according to claim 1, wherein the communication pipe exit section has an opening section at a tip end, the opening section being inserted into the suction hole.
 4. The sealed compressor according to claim 1, wherein the cylinder head is formed with a hollow space on a projection plane formed by projecting the suction hole in the lateral direction to the lower portion of the cylinder head.
 5. The sealed compressor according to claim 1, wherein the communication pipe exit section is provided with a heat insulating space isolated from the sealed space, on an outer periphery facing the valve plate, and a communication hole which provides communication between the heat insulating space and an interior of the communication pipe exit section.
 6. The sealed compressor according to claim 5, wherein the suction muffler is molded by use of a resin, and wherein the heat insulating space is formed integrally with the suction muffler, when the suction muffler is molded.
 7. The sealed compressor according to claim 1, being configured to be driven at one of a plurality of operating frequencies.
 8. A refrigeration device comprising a refrigeration circuit configured such that the sealed compressor as recited in claim 1, a heat radiator, a pressure-reducing device, and a heat absorbing unit are annularly coupled to each other by use of a pipe. 